No Sir I'm Not The One But I Do Know He Likes Cheese - Tumblr Posts

I want a book where the main character is the chosen one, but he doesn't want to be and instead of complaining while doing the task required he just tells people he knows the chosen one. It would go like:

"Me? No, sorry ma'am I'm not the chosen one, but I do know him tho. He makes good eggs"

Or then again:

"The chosen one? Oh, no I don't know where he is, but he does like to go to the movies"

And at the end of the book he just meets the villain and tells them the same thing he tells everyone.

"Oh, no mate, I'm not the one you're searching, but if you do meet him tell him Robert asked for cake"